Biomedical subjects

J Zenk

Publications and source records attributed to J Zenk.

At least 19 recordsLinked to original sources

PubMed2001

Transoral removal of submandibular stones.

OBJECTIVE: To assess transoral treatment of submandibular lithiasis. DESIGN: Study of a series of patients with submandibular stones undergoing transoral removal of the sialoliths. Duration of follow-up: 6 months to 7 years. SETTING: Department of Otorhinolaryngology, Head and Neck Surgery, University of Erlangen-Nuremberg, Erlangen, Germany, center for treatment of salivary stones. PATIENTS: Two hundred thirty-one patients (127 females, 104 males) suffering from submandibular lithiasis had a mean age of 41.7 years (age range, 12-86 years). Stone location was distal to the edge of the mylohyoid muscle in 115 patients and proximal to the gland in 102 patients (mean size of sialoliths, 6.3 mm [range, 2-30 mm]). Fourteen other patients had 2 separate stones, one within the hilum and a smaller more proximal one within the gland. INTERVENTIONS: Transoral removal of the stones under local anesthesia and preservation of the submandibular gland. MAIN OUTCOME MEASURES: Complete removal of the stones, complications, and recurrence of the stones. RESULTS: All 115 patients with distal stone location, 93 (91%) of 102 patients with stones of the perihilar region, and 9 (64%) of the 14 patients with 2 separate stones in the hilum and parenchyma were free of stones. Submandibulectomy had to be carried out in 4 patients (1.7%). Recurrence of lithiasis and damage to the lingual nerve remained below 1%. CONCLUSIONS: Transoral removal should be the treatment of choice in patients with submandibular stones that can be palpated bimanually and localized by ultrasound within the perihilar region of the gland.

Adolescent↗

PubMed2001

[Results of an in vitro study and initial clinical application of a combined Ho:YAG-/Nd:YAG laser].

BACKGROUND AND OBJECTIVE: A combined Ho:YAG/Nd:YAG laser produces light with properties similar to the beams of the mainly coagulating Nd:YAG laser and the cutting CO2 laser alone. PATIENTS/METHODS: The combined laser was tested in vitro on pig tissue. Additionally, we used this new combined tool for enoral operations. RESULTS: An effect of the pulsed Ho:YAG laser was explosive-like tissue disruption and sprinkling of fragments. Simultaneous use of the Nd:YAG laser resulted in an enlarged zone of coagulation. Clinically, the laser-assisted intervention was inferior to the classic operational methods. CONCLUSIONS: Comparing the established CO2 laser and the Ho:YAG laser, the latter showed only the advantage of delivery via a flexible fiber. Sprinkling of tissue fragments and wide incisions are oncologically problematic. We conclude that this new tool is of minor value for otorhinolaryngologists and head and neck surgeons.

Animals↗

PubMed2001

Localized lymphadenopathy due to leishmanial infection.

A 25-year-old female patient presented with an isolated cervical lymph node enlargement several months after having returned from Spain and Latin America. She had no other signs or symptoms of disease. Leishmania infantum/chagasi was identified as the causative agent. With extended travel activities localized lymph node enlargement due to leishmanial infection should be included in the differential diagnosis of lymphadenopathy of unknown origin.

Adult↗

PubMed2001

A new device for frontal sinus endoscopy: first clinical report.

OBJECTIVE: Endoscopically or microscopically controlled paranasal sinus surgery currently represents the state of the art. For anatomic reasons the ostium of the frontal sinus and the frontal sinus itself are difficult to observe. Flexible endoscopes are often difficult to implement and do not provide enough light intensity to visualize all parts of the frontal sinus. MATERIALS AND METHODS: A specially curved rigid endoscope with a working channel of 1.5 mm that allows passage into the frontal sinus has been developed to manage this problem. The system was used on 15 patients during paranasal sinus surgery to evaluate possible indications and its clinical usefulness. RESULTS: The endoscope could be introduced into the frontal sinus after an ethmoidectomy had been performed in all of the patients. The anatomy of the sinus could be visualized with sufficient light intensity in 14 patients. The shadowing of the frontal sinus seen in CT was not due to polyps of the mucosa of the frontal sinus in all cases, but rather due to secretion with otherwise normal mucosa. In the cases with polyps, it was necessary to irrigate with saline solution to prevent the buoyant polyps from collapsing over the endoscope. The following specific indications for this endoscopic version were established during this first test: intraoperative and postoperative control of the frontal sinus, clinical evaluation of tumor growth into the frontal sinus, biopsies within the frontal sinus, and evaluation of fractures. CONCLUSION: The new device provides further insight within the field.

Adult↗

PubMed2001

Identification of leptin in human saliva.

Leptin is produced predominantly in adipose tissue but has recently also been found in gastric mucosa. It has been shown that the oral application of leptin induces neuronal activity in the brain stem of rodents. The objective of the present study was to identify this hormone in human saliva and to examine the production and stability of salivary leptin. We have demonstrated production of leptin in salivary glands and oral mucosa by RT-PCR, its storage by immunocytochemistry, and the release of the peptide by RIA. Chromatographic analysis and immunoblotting confirmed the identity of leptin. There is a strong linear correlation (r2 = 0.78) between leptin concentrations from simultaneously collected saliva and plasma samples (n = 61). Stimulation of saliva flow increases total leptin secretion up to 3-fold (P < 0.001). As to the stability of leptin in gastric fluid, we found the peptide was not degraded above pH 3.5. Additionally, salivary leptin remains stable up to 5 d at 4 C. With regard to the presence of leptin receptors in gastric mucosa, we suggest salivary leptin as being a possible ligand for gastric leptin receptors. Furthermore, the determination of leptin in saliva allows for noninvasive sample collection.

Adult↗

PubMed2001

Therapy of invasive mucoceles of the frontal sinus.

Mucoceles of the frontal sinus that extend into the orbits and the anterior cranial fossa can, in certain cases, be difficult to manage therapeutically and may lead to lethal complications. The surgeon will have to make a decision between an endonasal and an extranasal, transfacial procedure to provide an adequate access. Between 1995 and 1998 we treated 12 patients suffering from invasive mucoceles of the frontal sinus. The mucocele was localized medially in 7 cases and in the lateral part of the frontal sinus in 5 cases. Five of the patients exhibited destruction of the orbital roof and in 7 cases combined destruction of the orbital roof and the floor of the frontal sinus were noted. The posterior wall of the frontal sinus was destructed in 6 patients, with one patient additionally showing partial destruction of the anterior frontal sinus wall. The causes of mucocele formation were previous frontal sinus operations (n = 8) and frontal sinus fractures (n = 3). In one case the cause remained unknown. In 7 cases with a medially localized mucocele the mucocele was marsupialized using an endonasal access. The mucoceles with a lateral localization were osteoplastically operated via an external access. Here we performed median drainage in 3 cases and, in one case each, obliteration and cranialization of the frontal sinus. The follow-up period was 2.8 years on average. All patients were free of complaints immediately after the operation. Mucocele recurrence or other complications did not arise. The cosmetic results were satisfactory in all cases.

Adult↗

PubMed2000

[Diagnosis and therapy of pseudotumors of the orbits].

Orbital pseudotumor is a nonspecific inflammatory process of unknown etiology that can be divided histopathologically into three basic types: granulomatous, lymphoid, and sclerosing. Between 1995 and 1998, 12 patients with pseudotumor orbitae were treated in the ENT Department of the University of Saarland. Histopathological examination showed granulomatous type of pseudotumor in six, lymphoid in three, and sclerosing in three patients. In seven cases the pseudotumor orbitae were medially located and in four cases laterally. In one patient nearly all orbital structures were infiltrated. Diagnostic biopsy was taken endonasally in six cases, via medical orbitotomy in two cases, and via lateral orbitotomy in four cases. Due to their good delimitation lymphoid and sclerosing tumors were extracted completely during diagnostic biopsy and patients were free of complaints after a few weeks. The six patients with granulomatous pseudotumor were treated primarily with steroids after the diagnosis had been definitely confirmed by histology. In three of those six cases a second course of steroid therapy had to be given, with positive results in two cases. Follow-up was between 6 and 28 months (mean 16 months). There were no postoperative complications. The clinical and radiographic presentation of the pseudotumors can vary greatly. Therefore, the differential diagnosis of specific infections or neoplasms can only be established through diagnostic biopsy. Different rhinosurgical approaches provide clear biopsy results and in some cases the pseudotumor is even completely removed.

Adult↗

PubMed2000

The influence of noise on blood flow in the basilar artery (BA) - measurements with transcranial color-coded duplex sonography (TCCD).

Acoustic stimuli are being reported as a cause of changes in resistance in the basilar artery (BA). It was the aim of this study to investigate this effect under standardized conditions dependent upon the intensity of the evoking stimulus. Twenty healthy subjects with normal hearing (male/female 14/6; mean age 26.4 years) were exposed to 'pink noise' for periods of 2 min at 75, 85 and 95 dB(A). Parallel to this, the Doppler spectrum of the BA and both the Pourcelot resistance index and the Gosling pulsatility index were measured by means of transcranial color-coded Doppler sonography. In comparison with the base value (at rest) a significant increase in resistance was noted during noise exposure. The noise-induced resistance changes could be interpreted as a consequence of changes in activity of the various centers of the auditory pathway and cerebral function. Further animal experiments may prove the connection between BA blood flow and resistance and their changes depending on different acoustic stimuli or different hearing pathophysiology.

Acoustic Stimulation↗

PubMed1999

In vitro tissue effects of a combined Ho:YAG/Nd:YAG laser: sprinkling of tissue fragments by Ho:YAG laser light may be problematic for oncological interventions.

BACKGROUND AND OBJECTIVE: Surgery of soft tissue, for example, of the tongue or the liver, requires a cutting and coagulating device. Therefore, a combined Ho:YAG/Nd:YAG laser providing the laser beam of both systems together in one bare fiber seems to be useful. STUDY DESIGN/MATERIALS AND METHODS: We studied the effect of such a laser system in vitro on tongues of pigs. RESULTS: Combined application of both lasers results in vitro in a thicker coagulation zone in soft tissue (tongue). Tissue fragments possibly containing vital cells are sprinkled by the pulsed energy of the Ho:YAG laser up to a distance of 20 cm. CONCLUSION: Using the pulsed Ho:YAG laser for oncologic interventions seems to be problematic. Combined laser effect in vivo may result in better hemostasis.

Animals↗

PubMed1999

[Clinical and diagnostic findings of sialolithiasis].

INTRODUCTION: Sialolithiasis is one of the most common diseases of the salivary glands. Within the scope of a retrospective analysis we report on our clinical and diagnostic findings in the largest patient group suffering from sialolithiasis reported in literature. MATERIAL AND METHODS: Between 1987 and 1997, data from 635 patient histories and follow-up examinations were systematically collected and analysed to look for typical symptoms of sialolithiasis, locations of stones and possible risk factors. RESULTS: Sialoliths predominated among patients aged 30 and 70 years, with no male/female predilection. A total of 78.9% of all calculi were detected in the submandibular ducts and 21.1% in the ducts of the parotid glands. The sublingual gland and the smaller salivary glands were not affected. A simultaneous stone disease of the urinary tract or the bile duct system occurred by chance (4.3%). Even regular medication in cases of other systemic diseases cannot be considered cofactors in pathogenesis. CONCLUSION: Diagnosis of sialolithiasis is the result of careful consideration of patient histories demonstrating typical symptoms and clinical examination. Sonography is the first choice of imaging. Pathogenesis of sialolithiasis seems to be based on local factors within the salivary ducts and glands.

Adolescent↗

PubMed1999

[Hiccup].

Hiccup is defined as involuntary contractions of the diaphragm and the auxiliary respiratory muscles, mostly in irregular series, followed by glottic closure, thereby producing a typical "hiccupping" inspiration. This is a physiologic phenomenon, which already exists in utero. Hiccup is believed to be a gastrointestinal reflex; however, function and the reflex arch are hypothetical. Acute hiccup is distinguished from pathological, chronic hiccup, defined by a duration executing 48 h, or recurrent episodes. Among approximately 100 causes for hiccup, the most common are located in the gastrointestinal tract, with gastro-esophageal reflux as the most important. While the respiratory effect is generally negligible, alkalosis may ensue in tracheotomized patients due to hyperventilation. A stepwise management plan for patients with hiccup is presented. If simple physical maneuvers and causal therapy fail, or causal therapy is impossible, the treatment of choice is medical, with baclofen. Interruption of the reflex arch may be causal therapy or be considered as a last resort.

Adult↗

PubMed1998

[Long-term results of extracorporeal peizoelectric shock wave lithotripsy of parotid stones].

OBJECTIVE: To evaluate prospectively the recently developed method of extracorporeal shock-wave treatment of stones of the parotid gland. PATIENTS AND METHODS: 76 patients with symptomatic, sonographically proven, solitary stones of the parotid gland (36 females, 40 males; aged 2-80 years) were treated with extracorporeal piezoelectric shock-wave lithotripsy (ESWL) after failed conservative management (sialagogues, gland massage, duct bougie dilation). RESULTS: Parotid stones were no longer demonstrable after a mean follow-up time of 48 (6-71) months in 38 of the 76 patients; they were symptom-free and no new stones had formed. A residual, but symptom-free, stone was found in another 20 patients (26%) of whom 13 (17%) reported marked improvement after ESWL. No change from pretreatment symptoms occurred in five patients (7%) so that operative removal had to be performed. The success rate of the lithotripsy was independent of size and site of the stone. CONCLUSION: ESWL is the method of first choice in the treatment of parotid gland stones after unsuccessful conservative treatment and obviates operative gland removal in most cases.

Adolescent↗

PubMed1998

[Long-term experience with percutaneous endoscopic controlled gastrostomy (PEG) in ENT tumor patients].

Percutaneous endoscopically controlled gastrostomy (PEG) enables patients suffering from a tumor of the upper aerodigestive tract to receive direct gastric feedings. The procedure also avoids the social stigma of a nasal feeding tube. The results of 630 PEG procedures used in 555 patients suffering from various head and neck cancers are reported. The mean age of the patients was 58.0 years with a range from 11 to 92 years. The PEG procedure was carried out under local anesthesia in 60% of the cases and with general anesthesia in 40%. In 512 patients the initial PEG procedure was successful while 43 of the patients require a second PEG procedure after loss of the PEG. In 19 patients the PEG procedure was not successful because of tumor obstruction or it was not possible to perform endoscopy. Twenty-four patients were successfully treated in a second or third session. Although 97% (n = 563) of all 555 patients and 92% (n = 579) of all PEG procedures were successful. The mean duration of PEG use was 243 (range: 0-2271 days). In 66 patients (10.5%) complications occurred but severe complications developed in only 8 patients (1.3%). Operative interventions were necessary in two cases. No deaths resulted from the PEG. These findings show that the PEG technique is safe to do with only few complications when performed by a skilled team.

Adolescent↗

PubMed1998

[The diameter of the Stenon and Wharton ducts. Significance for diagnosis and therapy].

In assessing new minimally invasive diagnostic techniques (duct endoscopy) and therapy (lithotripsy) of salivary gland disease, it is of importance to know the true dimensions of the secretory ducts. Twenty-five ducts of the parotid gland and 20 ducts of the sub-mandibular gland were examined histologically at different points of their anatomic course and their in vivo diameters were evaluated using a previously determined formalin-induced shrinking factor. The mean diameter of Stensen's duct at four different points along its length ranged between 0.5 mm and 1.4 mm, depending on the site. A narrowing at the middle of the duct was striking. In all preparations examined, the minimum width of the secretory duct was located at the ostium. In Wharton's duct the narrowest duct diameter was also identified at the ostium. The mean values for the duct diameters ranged between 0.5 mm and 1.5 mm. For diagnostic and therapeutic purposes, endoscopes, balloon catheters and stone-extraction baskets should conform as much as possible to physiological duct widths. A diameter of 1.2 mm should be considered the upper limit for duct instruments. Our findings also suggest that in the case of salivary stone lithotripsy the best results will be achieved when the maximum size of a stone fragment does not exceed 1.2 mm.

Aged↗

PubMed1998

Cytotoxic and anti-proliferative effects of high-energy pulsed ultrasound (HEPUS) on human squamous cell carcinoma cells as compared to connective tissue fibroblasts.

The cytotoxic and anti-proliferative effects of high-energy pulsed ultrasound (HEPUS) on human squamous cell carcinoma cells cloned from the hypopharynx (FaDu) and benign connective tissue cells (fibroblasts) were investigated in vitro. Sonication was carried out using an experimental piezoelectric, self-focusing burst-signal transducer. To increase the induction of cavitation, the transducer used was specifically designed to produce multiple oscillations with a high negative pressure amplitude. In both cell lines tested, the application of 100, 800 and 2000 pulses resulted in a high reduction of vital cells. After 2000 pulses, 4.0 +/- 1.1% of the fibroblasts but only 2.0 +/- 0.4% of the FaDu cells survived HEPUS exposure. A postexposure inhibiting effect of HEPUS for 10 days on the proliferation of surviving cells was noted for the FaDu cells exposed to 2000 pulses, but not as much for the fibroblasts. These findings support the hypothesis that human squamous cell carcinoma cells of the hypopharynx might be more sensitive to HEPUS than fibroblasts and that total tumor cell ablation might be possible in vitro given a sufficient number of HEPUS pulses.

Carcinoma, Squamous Cell↗

PubMed1998

Diameters of the main excretory ducts of the adult human submandibular and parotid gland: a histologic study.

In assessing new minimally invasive diagnostic techniques (duct endoscopy) and therapy (lithotripsy), it is of importance to know the true dimensions of the excretory ducts. Twenty-five ducts of the parotid gland and 20 ducts of the submandibular gland were examined histologically at different points of their anatomic course, and their in vivo diameters were evaluated with the use of a previously determined formalin-induced shrinking-factor. The mean diameter of Stensen's duct at four different points along its length ranged between 1.4 mm and 0.5 mm, with a maximum of 2.3 mm and a minimum of 0.1 mm, depending on the site. A narrowing at the middle of the duct was striking. In all preparations examined, the minimum width of the excretory duct was located at the ostium. In Wharton's duct the narrowest duct diameter was also identified at the ostium. The mean values for the duct diameters ranged between 1.5 mm and 0.5 mm. The largest duct diameter reached 2.2 mm; the smallest one, 0.2 mm. For diagnostic and therapeutic purposes, endoscopes, balloon catheters, and stone-extraction-baskets probably should, despite the extensibility of the duct, conform as much as possible to the physiologic duct widths. A diameter of 1.2 mm should be aimed at as an upper limit for these instruments. Our findings also suggest that, in the case of salivary stone lithotripsy, the best results will be achieved when the maximum size of stone fragments does not exceed 1.2 mm.

Adult↗

PubMed1998

[Treatment of deep neck infections].

BACKGROUND: The incidence of deep neck space infections has been significantly reduced by modern antibiotic therapy. These infections are relatively rare and yet the life-threatening complications merit special consideration by head and neck surgeons. PATIENTS: Seven cases of deep neck space infections as a consequence of purulent pharyngitis (3), peritonsillar abscess (2), retropharyngeal (1), and odontogenic (1) abscess are presented. Despite antibiotic therapy according to antibiogram all patients showed an increase in complaints with persisting febrile temperatures and rising inflammation parameters. Surgical intervention became necessary. In two cases the infection spread into the mediastinum. RESULTS: All patients were completely cured by means of early surgical intervention including extensive drainage of the primary focus, deep neck spaces and mediastinum, accompanied by intravenous antibiotic therapy. Tracheotomy was performed on one patient with increasing dyspnea. All patients had an uneventful recovery without major postoperative complications. CONCLUSIONS: The clinical course of the disease must be observed particularly closely even after starting antibiotic therapy and identification of the infectious focus. Antibiotic therapy may in some cases cover clinical symptoms. However, in the presence of abscess formation or necrotizing infections, antibiotics can prove to be ineffective. The optimum time for surgery is difficult to determine. Complete drainage of the neck spaces down to the mediastinum is a safe procedure to save the patients' life. This shortens the duration of the disease and prevents complications. The most common problems in the management of deep neck space infections are discussed.

Abscess↗

PubMed1998

Extracorporeal shock wave lithotripsy of parotid stones. Results of a prospective clinical trial.

The extracorporeal shock wave treatment of parotid stones is a rather new therapy. Its usefulness was determined in a prospective study. Seventy-six patients (36 female, 40 male, 2 to 80 years of age) with symptomatic, sonographically detectable solitary sialoliths of the parotid gland were treated with an extracorporeal piezoelectric shock wave therapy after unsuccessful conservative therapy (sialagogues, gland massage, bougienage of the secretory duct). At most, 3 treatments per patient were performed. Altogether, 38 of the 76 patients (50%) were free of stones and no longer suffered from complaints after completion of shock wave treatment and a mean follow-up period of 48 months (range 6 to 71 months). During the follow-up period, in no case could renewed stone formation be observed. Residual stone fragments were detectable in 20 patients (26%), but did not cause further symptoms. Thirteen patients (17%) with residual stone fragments stated a significant improvement of their complaints after therapy. Five patients (7%) did not observe any changes of their pretherapeutic complaints and underwent parotidectomy. The therapeutic success was not influenced by stone size or by stone localization within the gland. During the follow-up period, no side effects of the therapy were identified. With stones of the parotid gland, extracorporeal shock wave lithotripsy is -- after one has used conservative therapies (sialagogues, gland massage) -- the treatment of choice, avoiding in the majority of cases a parotidectomy with its operative risks (paresis of the facial nerve, Frey's syndrome).

Adolescent↗